Material cutting method and apparatus

ABSTRACT

Apparatus for cutting material comprises first and second rotatable members defining a nip through which the material passes and at which cutting is effected by dies carried by the rotatable member. Actuating means operates to shift one of the members away from the other member to render the dies ineffective to cut the material. The actuating means is operated in response to the presence of a previously cut portion of material being carried on a die plate carried by one of the members.

United States Patent Inventor Albert]. Saris Fairview Park, Ohio Appl. No. 765,150

Filed Oct. 4, 1968 Patented Sept. 14,1971

Assignee llarris-1ntertype Corporation Cleveland, Ohio MATERIAL CUTTING METHOD AND APPARATUS 9 Claims, 8 Drawing Figs.

US. Cl 83/37, 83/61, 83/300, 83/358, 83/333 Int. Cl B23d25/02. 826d 5/00 Field of Search 83/37,61,

1 1 References Cited UNITED STATES PATENTS 1,008,932 1 1/191 1 Walther 83/563 X 2,122,796 7/1938 Horton.... 83/61 X 3,430,542 3/1969 Sarka 93/36 A UX Primary Examiner-Andrew R. Juhasz Assistant Examiner-Leon Gilden AttorneyYount, Flynn & Tarolli ABSTRACT: Apparatus for cutting material comprises first and second rotatable members defining a nip through which the material passes and at which cutting is effected by dies carried by the rotatable member. Actuating means operates to shift one of the members away from the other member to render the dies ineffective to cut the material. The actuating means is operated in response to the presence of a previously cut portion of material being carried on a die plate carried by one of the members.

PATENTED SEPI 41971 SHEET 1 (IF 2 MAM TK NMJM ES v 0 J n m m M NW4 Y B 1. B (13 Cl A E ag Eh Zia L PATENTEU SEPI 41971 3 604 296 saw 2 OF 2 /NVENTOR 141.5597 cf S/WKA A 7'TORNE YS MATERIAL CUTTING METHOD AND APPARATUS The present invention relates to a material-cutting method and apparatus, and more particularly relates to a materialcutting method and apparatus wherein rotating members cooperate to cut sheet material advancing therebetween.

Certain material-cutting apparatus includes rotating nipforming cylinders which are operable to cut sheetlike material advancing through the nip. The material advancing through the nip is cut by dies carried for rotation with the respective cylinders, and which dies are registerable with each other at the nip to cut the material advancing through the nip to provide a particularly configured cutout portion of the material. An example of such a cutout portion is a carton blank which, when separated from the adjacent sheetlike material, may be folded into a carton or boxlike container. In some cases, the cutting is effected by lands which extend radially from the periphery of the cylinders and engage opposite sides of the sheetlike material at the nip to effect rupture cutting thereof as the material passes through the nip. The lands are formed on die plates which consist of thin, flexible, metallic sheets which are bent around the periphery of the cylinders and are clamped to the cylinders in their bent condition.

In some cases material which is cut by the aforementioned lands at the cutting nip becomes separated from the sheet advancing through the nip and remains on the die plate on one of the cylinders, frequently because of lodging of the material between lands on the die plate. Additional cutout portions of the material may also become lodged between the same lands so that a buildup of multiple thicknesses of the sheet material between the lands occurs. If material continues to become lodged between the lands, eventually the die plate is squeezed, or dimpled, by this buildup of material, causing the lands to be shifted and resulting in misalignment of lands on the respective die plates at the cutting nip so that the material advancing therethrough is not properly cut by the lands. Moreover, the portions of the sheetlike material which have accumulated on the die plate cause the material forming the die plate to yield beyond its elastic limit, and the die plate thus affected cannot be repaired and must be replaced. Such die plates are relatively expensive, making replacement thereof costly and additionally lost time is encountered in replacing the damaged die plate. Moreover, the material wastage of imperfectly cut sheets of material is also a result of this problem.

Accordingly, a principal object of the present invention is the provision of a new and improved material-cutting method and apparatus wherein the cutting is effected by rotating members which cooperate to form a cutting nip and the cutting operation is terminated in response to the presence of a previously cut portion of the material being carried with one of the rotating members.

Another object of the present invention is the provision of a new and improved material-cutting apparatus including first and second rotatable nip forming cylinders having die plates carried thereon and which die plates have projecting lands for cutting sheetlike material advancing through the nip, and wherein means is provided for producing a control signal in response to the presence of previously cut material located between lands on a die plate of one cylinder and wherein the apparatus is rendered ineffective to further cut material in response to the control signal.

A further object of the present invention is the provision of a new and improved apparatus for handling sheet material including rotatable nip forming cylinders carrying die plates which are effective to cut sheetlike material advancing through the nip, and wherein sensing means is provided adjacent a periphery of one of the cylinders to detect the presence of a previously cut portion of the material on the die plate of the one cylinder and to initiate performance of a control function.

A still further object of the present invention is the provision of a new and improved apparatus for cutting sheet material, as set forth in the next preceding paragraph, wherein the sensing means includes a photosensitive which is operable to sense light reflected from a previously cut portion of sheet material on a die plate of one of the cylinders and produce a signal in response thereto and wherein the apparatus additionally includes control means for receiving the signal from the photosensitive device and producing an output signal 'in response thereto, and actuating means operable in response to the output signal to shift one of the cylinders relative to the other cylinder to prevent further cutting of the material at the cutting nip.

Other objects and advantages of the present invention will become apparent from a consideration of the following detailed description thereof and from the drawings which form a part of this specification and wherein:

FIG. 1 is a diagrammatical view of an apparatus embodying the present invention;

FIG. 2 is a fragmentary perspective view of a portion of the apparatus of FIG. 1;

FIG. 3 is a sectional view of a portion of the apparatus taken approximately at lines 33 of FIG. 4;

FIG. 4 is a fragmentary elevational view of a portion of the apparatus embodying the present invention;

FIG. 5 is a plan view of a portion of a sheet of material handled by the apparatus;

FIG. 6 is a fragmentary sectional view of a portion of the apparatus of FIG. 1 in one operative condition thereof;

FIG. 7 is a fragmentary sectional view of a portion of the apparatus of FIG. 1 in another operable condition thereof; and

FIG. 8 is a fragmentary sectional view of a portion of a prior art cutting apparatus.

The present invention provides a new and improved method and apparatus for cutting sheetlike material in web or sheet form. The apparatus includes in general nip-forming members carrying die plates thereon operable to cut sheetlike material advanced through the nip. More particularly, the present invention provides an apparatus, of the type mentioned wherein means are provided for sensing previously cut material on one of the die plates and for rendering the apparatus ineffective to cut additional material in response to detection of such previously cut material so that possible destruction of the die plates due to an accumulation of previously cut material on the die plates is minimized. While the invention is preferably embodied in one particular type of rotary material-cutting apparatus, it should be apparent that the present invention may be utilized in conjunction with other material-handling apparatus different from that which is described and illustrated herein.

A material-processing apparatus 10 embodying the invention is illustrated in FIG. 1. The apparatus 10 includes a material-cutting mechanism 11 and a material-feeding mechanism 12. The feeding mechanism 12, which has been diagrammatically illustrated, includes parts operable to remove a sheet of material from a pile 13 of sheets, supported on a conventional pile elevator generally designated 14, and feed the sheets individually to the material-cutting mechanism 11. Material which has been cut is guided from the apparatus 10 to subsequent material-handling operations by a suitable tape conveyor mechanism 15, only a portion of which is shown.

Preferably the material which is processed by the apparatus 10 is cardboard sheet material having the outline of a plurality of carton blanks printed thereon in a closely spaced relation and lying in rows on the material with each row extending in the direction of the feed of the material. The sheet material is thus cut providing a plurality of the carton blanks spaced immediately adjacent each other and in a row. The sheet material is so dimensioned that a plurality of rows of carton blanks are preferably cut from each sheet.

A portion of a sheet which is to be processed by the apparatus 10 is shown in FIG. 5 with an arrow 20 indicating the direction of feed of the material. Two rows designated 21, 22 of printed carton blank images designated 23 are illustrated with the carton blanks arranged in the rows in a suitable number, though only one carton blank image 23 is illustrated in each row 21, 22 of FIG. 5. The printed images 23 are placed on the sheet material in a so called reverse nested" arrangement, that is where projections 24 of the images in row 21 coextend with similar projections 25 in the images of row 22. The coextension of the projections 25 is provided by reversing the direction of orientation of the images in the row 22 from those in the row 21. For reasons which will become apparent hereinafter, the printed images of the cartons are on the upper side of the sheet as viewed in the drawing and the lower side of the sheet is generally devoid of markings.

Each printed image 23 contains an area designated A which may be termed an internal waste area and which will becomes waste material. The portions A are termed internal waste" or broke and are illustrated in FIG. by way of example only. The portion of the sheet material which surrounds the printed images 23 constitutes waste material as well and is termed extemal waste. The internal waste or broke may constitute a variety of waste portions depending upon the type of carton blank and its configuration.

Sheet material in the general form just described, is delivered in registered relation to the cutting mechanism 11 by the feeding mechanism 12 as previously noted. The cutting mechanism 1 1 includes a pair of rotary cylinders 26, 27, which have their peripheral surfaces adjacent each other to define a cutting nip 28 therebetween so that the sheet material is cut as it advances through the nip 28.

The cylinders 26, 27 carry projecting members which engage opposite sides of the sheet as it passes through the nip to effect rupture cutting of the sheet, and these projecting members are preferably lands 30. The lands 30 are carried by flexible die plates 31, 32 removably secured to the cylinders 26, 27 respectively. Preferably the die plates 31, 32 are secured to their respective cylinders by suitable clamps 31a, 32a located at the gaps of the cylinders and which have been illustrated by schematic representations in FIG. 1.

The plates 31, 32 are positioned with respect to the cylinders 26, 27 so that the cutting lands 30 engage the opposite sides of the material at the nip 28 to rupture cut the material at desired locations in registered relationship with the printed images 23 on the material. In the event that it is desired to change the type of carton to be formed by the cutting mechanism, the plates 31, 32 are removed from the cylinders by releasing the clamps 31a, 32a and are replaced by other suitable constructed die plates. Rupture cutting of the material is effected when overlapping lands on the respective cylinders engage the sheetlike material under pressure at the nip and cut the material without contacting each other. The specific construction of the die plates 31, 32 and the specific cutting modes are known and disclosed in the U.S. Pat. No. 3,142,233, to Downie and thus will not be described in detail. In should be noted that the die plates of the respective cylinders my also be provided with lands which are efiective to crease the material advancing through the nip 28 so that the carton blanks, after separation from the adjacent sheet material may be readily folded into their finished carton form, however the necessary lands for providing such creasing of the carton blanks have not been illustrated.

The cylinders 26, 27 are supported at their opposite ends by side frames, only one of which 40, is shown in the drawings. As best seen in FIG. 3, the cylinder 26 includes a shaft portion 260 extending from the end thereof toward the side frame 40. The side frame 40 includes bearings 41 positioned therein which receive the cylinder shaft 260 to support the cylinder 26 for rotation with respect to the side frame 40. The bearing 41 is mounted in an eccentric member 42 which is supported in an opening or bore 43 in the side frame 40. The eccentric member 42 is rotatable in the bore 43 to move the cylinder 26 toward and away from its operating position wherein material is cut at the nip 28 between the cylinders 26, 27. The eccentric member 42 is rotated to effect this movement by a fluid pressure actuating means 46.

As illustrated in FIG. 4 the actuating means 46 includes a double acting piston-cylinder actuator 47, which is preferably hydraulically operated, and a linkage 48 connected between the actuator 47 and the eccentric member 42. The actuator 47 is connected by a clevis to a suitable bracket 50 mounted on the side frame 40 so that the actuator may rotate slightly about the clevis connection while transmitting force along its longitudinal axis. The linkage 48 includes a rocker arm 51 rotatably supported on the side frame 40 and a link 52 con nected between the rocker arm and the eccentric member 42. The rocker arm 51 is supported by a shaft 53 and is connected to the piston rod 54 of the actuator 47 by a clevis connection 55 which permits rotation between the rocker arm and piston rod as the actuator effects rotation of the rocker arm. The link 52 is connected to the rocker arm 51 and the eccentric member 42 by suitable clevises 56, 57 at its opposite ends and includes threaded parts 58 intermediate its ends which permit adjustment of the length of the link.

Application of fluid pressure to the actuator 47 is controlled by the operation of a solenoid valve V connected between a source of high-pressure fluid and the actuator. When the valve V is operated to produce upward movement of the piston, as viewed in the drawings, the eccentric member 42 is rotated in a counterclockwise direction through the linkage 48 to move the axis of rotation of the cylinder 26 upwardly and along a circular path about the axis Y of the bore 43 in the side frame 40 so that the cylinder 26 is bodily shifted laterally or radially away from the cylinder 27. When the valve V is in its condition wherein the piston of the actuator 47 moves downwardly as viewed in the drawings, the axis of rotation X of the cylinder 26 is moved downwardly toward the cylinder 27 to its working position. A stop 59 engageable with the rocker arm 51 limits downward shifting of the cylinder 26.

The supporting structure for the projecting shaft on the other end of the cylinder 26 generally corresponds to the described structure on the cylinder shaft 26a and includes a bearing, an eccentric member, and fluid pressure actuating means corresponding to the bearing 22, eccentric 42, and the actuator 47.

The cylinder 26 may be adjusted axially relative to the cylinder 27 by rotating an adjusting member 66 keyed to a shaft 67 connected to and projecting axially from the outer end of the cylinder 26a. The shaft 67 is connected to the shaft 26a by a bracket 70 secured to the outer end of the shaft 26a by screws '71. The bracket 71 includes an opening 72 on the end which receives the inner end of the shaft 67 which shaft includes a shoulder portion 73 thereon inside the bracket 70 and a shoulder 74 adjacent the outer side of the bracket 70. The shoulder 73 is formed by an enlarged portion of the shaft 67 while the shoulder 74 is provided by a nut threaded onto the shaft 67 to provide for adjustment of the shoulder 74. Axial movement of the shaft 67 is transmitted to the bracket 70 and in turn to the cylinder 26 by thrust bearings disposed between the shoulders 73, 74 and an annular wall 75 projecting inwardly from the sidewall of the opening 72. The thrust bearings, while transmitting axial movement of the shaft 67 to the cylinder 26, permit the cylinder 26 to rotate relative to the shaft 67. The member 66 which is rotated to effect the axial adjustment is positioned on a reduced portion of the shaft 67 and which extends outwardly from the bracket 70 through a cover member 67b fixed to the eccentric member 42. The reduced outer end portion is threaded into the opening in the cover member 67b and when the adjusting member 66 is rotated the shaft 67 is threaded into or out of the cover member 6712 to adjust the axial position of the cylinder 26. A lock nut 67a is provided to lock the shaft 67 to the cover member 67b.

From the above it should be apparent that the cylinder 26 is supported in the side frames for rotation and for translational movement thereof relative to the side frames. The cylinder 27, as noted above, is also rotatably supported in the side frames by a suitable bearing structure which permits that cylinder to rotate relative to the frames. The cylinder 27 is, however,

fixed against translational movement relative to the side frames. The bearing structures for supporting cylinder 27 of the preferred embodiment are conventional and therefore have not been illustrated. The aforementioned axial adjustment of the cylinder 26 permits the lands 30 on the respective cylinders 26, 27 to be aligned in a suitable cutting relationship with each other when the die plates have been clamped to the cylinders.

In the illustrated embodiment the cylinders 26, 27, are driven from an electric motor 80, shown schematically in FIG. 1, through a conventional linkage 81 such as a gear train so that the cylinders 26, 27 are rotated in opposite rotational directions and at identical surface speeds. Preferably the cylinders 26, 27, carry meshed spur gears, not shown, at one end thereof, which are nonrotatably connected to the cylinders to provide for driving of one cylinder by the other. The motor 80 also drives the feeding means 12 by way of a conventional drive train 82 which has not been illustrated in detail.

Portions of the sheet material cut in the cutting mechanism 11 at times remain attached to the die plates mounted on the cylinders 26, 27. More specifically, in a cutting mechanism of the type illustrated herein the boundaries of certain lands on one die plate enclose a smaller area than do the cooperating lands on the other die plate so that proper cutting relationship between the lands can be achieved (see FIGS. 6 & 7). As a result of this size relationship between the lands or dies of the respective die plates, certain parts of the material which is cut tend to be pushed toward the lands enclosing the larger area and can become lodged between the lands on that die plate and remain attached to the die plate. In certain die layouts the cartons themselves also could become lodged in the dies. The particular dimensioning of the die is disclosed in US. Pat. No. 3,142,233 to Downie. A particular example of proper dimensioning is as follows: land width 0.062 inch, die thickness 0.035 inch, the depth of each is about 0.005 inch less than the stock thickness.

In the illustrated embodiment the cylinder 26 carries the cutting die on which the material tends to remain. Most frequently, the portion of the sheet material which becomes lodged between the lands is the small-sized material pieces forming the internal waste or broke, designated A. FIGS. 68 illustrate such an occurrence. However, other material portions may also become lodged between the lands.

As illustrated in FIG. 6 the internal broke area A is approaching the nip and with the leading edge of the broke A being rupture out between cooperating lands 30a, 30b on the cylinders 26, 27, respectively, and with the leading edge of the broke A urged into engagement with a side 300 of the land portion 301: on the cylinder 26. As illustrated in FIG. 7, the trailing edge of the broke A is cut at the nip 28 by land portions on the respective cylinders, and the trailing edge of the broke A may become lodged against the side 30d of the land portion 301: on the cylinder 26 so that the broke A is held between the adjacent sides 30c, 30d of the land portions 30a on the die plate 31 of the cylinder 26.

FIG. 8 is illustrative of the relationship between the die plates at the nip 28 after a broke area A has become lodged between adjacent lands on the die plate 31 of the cylinder 26 and it should be apparent from this illustration that the previously cut broke portion A between the adjacent sides of the lands 30a of the die plate 31 have resulted in dimpling and yielding of the die plate during continued rotation thereof. This affects the proper cutting by the lands. In fact the dimpling can be to such an extent that the lands on the die plate 31 move toward each other peripherally of the die plate 31 and become aligned with the cooperating land portions on the die plate 32 so that cutting out of subsequent portions A of the sheet material is not possible. The die plate 31 is thus no longer suitable for use in the apparatus since the portion P of the plate between the lands forming the broke cutting die has yielded and cannot be satisfactorily repaired. In such an instant the die plate 31 must be replaced by a similar die plate which replacement, as noted above, is not only expensive, but

requires a certain amount of time during which the processing apparatus 10 is not productive.

In accordance with the present invention, means is provided for performing a control function to render the apparatus ineffective to cut material, in response to the presence ofa previously cut portion of the material on a die plate of one of the cylinders. As illustrated in FIG. 1, the means 85 includes control means 87 for initiating operation of the actuating means 46 to effect shifting of the cylinder 26 away from the cylinder 27, and detecting means 88 for rendering the control means operable in response to the presence of a previously cut portion of the sheet material on the die plate 31 of the cylinder 26. The control means 87 is electrically connected to a suitable power supply and includes an output cir cuit which controls operation of the valve V which in turn is operable to control the application of fluid pressure to the piston of the actuator 47. The valve V may be of any suitable construction and therefore is not illustrated in detail. The control means 87 is rendered operative to actuate the valve V in response to a control signal received from the detecting means 88. The control means 87 also acts to stop the entire materialprocessing apparatus 10 in any suitable manner.

The detecting means 88 preferably includes a photosensitive element 90 which produces an electrical signal in response to a change in intensity of light incident thereon, and a light source 91. The sensing element 90 is connected in an input circuit of the control means 87 so that a signal produced thereby renders the control means operative. As best seen in FIGS. 2 and 4, the sensing element 90 and the light source 91 are mounted in a suitable housing 94 which is connected to a rod member 95 supported at its ends by the side frames of the apparatus adjacent the periphery of the cylinder 26 at a location beyond the nip 28 in the feeding direction. Preferably a plurality of detecting means 88 are supported on the rod 95 although only two are shown in FIG. 2. Each of the means 88 is movably supported on the rod 95 by a member which is slidable on the rod axially relative to the cylinders and a bracket 101 interconnected between the member 100 and the housing 94 so that each detecting means 88 is unitarily mova ble relative to the cylinder 26 for adjustment purposes.

Prior to operation of the apparatus, the detecting means are moved along the rod 95 to desired locations adjacent the periphery of the cylinder 26. The light source 91, which may be a suitable incandescent bulb, is energized to direct a beam of light onto the die plate 31 and which is reflected onto the photosensitive element 90. The cylinders 26, 27 and the feeding means 12 are then driven to cut the material at the nip 28 as described.

In the event that a portion of the material should become lodged between the lands of the cutting die, as illustrated in FIGS. 6 and 7, a light beam from the light source 91 of a detecting means 88 is reflected from that portion of the material to the element 90. Due to the difference in reflective properties of the unprinted side of the sheet and the die plate 31, the light beam reflected from the broke portion A of the material is of different intensity than that light reflected from the die plate 31 itself. Moreover, the light reflected by the broke is also of greater intensity than the lights reflected when the gap of the cylinder passes the detecting means 88. When the broke reflects light to the sensing element 90 an input signal is transmitted from the element 90 to the control means 87. As noted above, control means 87 is constructed so that upon receipt of an input signal from the detecting means, an output circuit is established which is effective to stop the apparatus 10 and to control operation of the valve V to shift the cylinder 26 laterally away from the cylinder 27 and thereby render the apparatus ineffective to out further sheets of the material. The operator can then remove any material on the die plate 31 and render the cutting unit operative to cut additional sheets, with a minimum amount of lost time and without damage to the die plate which might otherwise occur.

It should be apparent that any reasonable number of detecting means may be incorporated in the processing apparatus 10 ,7 .7- and these means may be positioned adjacent various portions of the die plate 31 upon which any previously cut portions of the material might be carried. it should further be apparent that an input signal from any one of the photosensitive elements 90 results in the apparatus being stopped and the cylinder 26 being shifted away from the cylinder 27.

Although a single preferred embodiment of the present invention has been illustrated and described herein in considerable-detail, the present invention is not to be considered as limited to the precise construction shown, for example, a material-processing apparatus embodying the present invention could be constructed so that upon sensing of a previously cut portion of the material on one of the die plates, the feed of sheet material to the cutting mechanism could be stopped to render the apparatus ineffective to cut material. It is therefore my intention to hereby cover all adaptations, modifications and uses of apparatus embodying the present invention which come within the scope of the appended claims.

Having described my invention, I claim:

1. Apparatus for cutting material comprising first and second rotatable members adapted to support die plates with cutting elements thereon, said members with the die plates thereon defining a nip through which the material passes and at which cutting is effected by the dies, actuating means for shifting one of said members away from said other member to render said die plates ineffective to cut the material, and means for effecting operation of said actuating means in response to the presence of a previously cut portion of material being carried on a die plate of one of said members to prevent further cutting of material thereby.

2. Apparatus as defined in claim I wherein said means for effecting operation of said actuating means includes sensing means positioned adjacent said first member and operable to detect the presence of the material on the die plate supported by said first member.

3. Apparatus as defined in claim 2 wherein said sensing means includes an element effective to detect changes in light incident thereon as a result of previously cut material being carried on the die plate supported by said first member.

4. Apparatus as defined in claim 3 wherein said sensing means includes a plurality of photosensitive elements positioned adjacent axially spaced locations of said fist member with said photosensitive elements effective to produce a control signal in response to the presence of said previously cut material on said die plate of said first member.

5. Apparatus as defined in claim 2 wherein said sensing means comprises a plurality of sensing elements located axially along said first member adjacent a periphery thereof, each of said elements being adjustably movable axially of said first member.

6. Apparatus as defined in claim 2 wherein said cutting elements comprise lands supported on die plates carried by said members and wherein cooperating lands on said first and second members cut material at said nip and urge cut material toward said lands on said first member.

'7. Apparatus for cutting sheetlike material comprising, first and second rotatable cylinders having die plates on the peripheries thereof, said cylinders supported for rotation adjacent each other to define a nip therebetween at which portions of the die plates engage opposite sides of the material advancing through said nip to effect cutting thereof, a feeding mechanism for advancing material toward said nip, an actuating mechanism for shifting one of said cylinders toward and away from the other cylinder, and means for detecting the presence of a previously cut portion of the sheet material on a die plate of one of said cylinders and for operating one of said mechanism to prevent further cutting of the material, said actuating mechanism comprising means operable to shift said one of said cylinders away from the other cylinder in response to detection of a portion of the material on said die plate.

8. Apparatus for performing a cutting operation on sheetlike material comprising, first and second rotatable cylinders supported adjacent each other to provide a nip therebetween, eac of said cylinders supporting die plates t ereon forming peripheries of the cylinders, said die plates including parts engageable with the material at said nip to effect cutting thereof as the material is advanced through said nip, means for providing a control signal in response to the presence of a previously cut portion of the material on a die plate of one of said cylinders, and actuating means operated in response to said control signal for shifting one of said cylinders away from said other cylinder to render said die plates ineffective to cut the material.

9. A method of cutting sheetlike material into articles and waste by apparatus comprising first and second rotatable nipforming members carrying die plates thereon comprising the steps of, advancing sheetlike material toward said nip, cutting said material at said nip as the material advances therethrough, directing the cut sheetlike material away from said nip, photoelectrically detecting any out portion of the material on a die plate of one of said members, producing a control signal in response to detection of a cut portion of material, and preventing further cutting of the sheetlike material in response to said signal, said step of preventing further cutting including the step of shifting one of said rotatable members away from said other members. 

1. Apparatus for cutting matErial comprising first and second rotatable members adapted to support die plates with cutting elements thereon, said members with the die plates thereon defining a nip through which the material passes and at which cutting is effected by the dies, actuating means for shifting one of said members away from said other member to render said die plates ineffective to cut the material, and means for effecting operation of said actuating means in response to the presence of a previously cut portion of material being carried on a die plate of one of said members to prevent further cutting of material thereby.
 2. Apparatus as defined in claim 1 wherein said means for effecting operation of said actuating means includes sensing means positioned adjacent said first member and operable to detect the presence of the material on the die plate supported by said first member.
 3. Apparatus as defined in claim 2 wherein said sensing means includes an element effective to detect changes in light incident thereon as a result of previously cut material being carried on the die plate supported by said first member.
 4. Apparatus as defined in claim 3 wherein said sensing means includes a plurality of photosensitive elements positioned adjacent axially spaced locations of said fist member with said photosensitive elements effective to produce a control signal in response to the presence of said previously cut material on said die plate of said first member.
 5. Apparatus as defined in claim 2 wherein said sensing means comprises a plurality of sensing elements located axially along said first member adjacent a periphery thereof, each of said elements being adjustably movable axially of said first member.
 6. Apparatus as defined in claim 2 wherein said cutting elements comprise lands supported on die plates carried by said members and wherein cooperating lands on said first and second members cut material at said nip and urge cut material toward said lands on said first member.
 7. Apparatus for cutting sheetlike material comprising, first and second rotatable cylinders having die plates on the peripheries thereof, said cylinders supported for rotation adjacent each other to define a nip therebetween at which portions of the die plates engage opposite sides of the material advancing through said nip to effect cutting thereof, a feeding mechanism for advancing material toward said nip, an actuating mechanism for shifting one of said cylinders toward and away from the other cylinder, and means for detecting the presence of a previously cut portion of the sheet material on a die plate of one of said cylinders and for operating one of said mechanism to prevent further cutting of the material, said actuating mechanism comprising means operable to shift said one of said cylinders away from the other cylinder in response to detection of a portion of the material on said die plate.
 8. Apparatus for performing a cutting operation on sheetlike material comprising, first and second rotatable cylinders supported adjacent each other to provide a nip therebetween, each of said cylinders supporting die plates thereon forming peripheries of the cylinders, said die plates including parts engageable with the material at said nip to effect cutting thereof as the material is advanced through said nip, means for providing a control signal in response to the presence of a previously cut portion of the material on a die plate of one of said cylinders, and actuating means operated in response to said control signal for shifting one of said cylinders away from said other cylinder to render said die plates ineffective to cut the material.
 9. A method of cutting sheetlike material into articles and waste by apparatus comprising first and second rotatable nip-forming members carrying die plates thereon comprising the steps of, advancing sheetlike material toward said nip, cutting said material at said nip as the material advances therethrough, directing the cut sheetlike material away from said nip, phoToelectrically detecting any cut portion of the material on a die plate of one of said members, producing a control signal in response to detection of a cut portion of material, and preventing further cutting of the sheetlike material in response to said signal, said step of preventing further cutting including the step of shifting one of said rotatable members away from said other members. 